Vacuum pump



FIG. 1 is a top perspective view of a vacuum pump showing our new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a left side elevation view thereof;

FIG. 4 is a front elevation view thereof;

FIG. 5 is a right side elevation view thereof;

FIG. 6 is a rear elevation view thereof; and,

FIG. 7 is a bottom plan view thereof.

The depictions within the broken lines are for the purpose of illustrating portions of the vacuum pump that form no part of the claim. 

CLAIM The ornamental design for a vacuum pump, as shown and described. 